In conclusion, these data have revealed an hitherto unconsidered role of MC in recruiting antiviral CD8 T cells more efficiently to a relevant organ site of CMV disease, and thus predict that MC supplementation in recipients of hematopoietic (stem) cell transplantation could improve control of a primary or reactivated CMV infection for prevention of CMV pneumonia and, presumably, also of other organ manifestations of CMV disease. The gene discussed is CD8A; the disease is cytomegalovirus infection.